async ValueTask <GeoJSONObject> ReadGeometryCore(NpgsqlReadBuffer buf, bool async, BoundingBoxBuilder?boundingBox)
{
await buf.Ensure(SizeOfHeader, async);
var littleEndian = buf.ReadByte() > 0;
var type = (EwkbGeometryType)buf.ReadUInt32(littleEndian);
GeoJSONObject geometry;
NamedCRS? crs = null;
if (HasSrid(type))
{
await buf.Ensure(4, async);
crs = GetCrs(buf.ReadInt32(littleEndian));
}
switch (type & EwkbGeometryType.BaseType)
{
case EwkbGeometryType.Point:
{
await buf.Ensure(SizeOfPoint(type), async);
var position = ReadPosition(buf, type, littleEndian);
boundingBox?.Accumulate(position);
geometry = new Point(position);
break;
}
case EwkbGeometryType.LineString:
{
await buf.Ensure(SizeOfLength, async);
var coordinates = new Position[buf.ReadInt32(littleEndian)];
for (var i = 0; i < coordinates.Length; ++i)
{
await buf.Ensure(SizeOfPoint(type), async);
var position = ReadPosition(buf, type, littleEndian);
boundingBox?.Accumulate(position);
coordinates[i] = position;
}
geometry = new LineString(coordinates);
break;
}
case EwkbGeometryType.Polygon:
{
await buf.Ensure(SizeOfLength, async);
var lines = new LineString[buf.ReadInt32(littleEndian)];
for (var i = 0; i < lines.Length; ++i)
{
var coordinates = new Position[buf.ReadInt32(littleEndian)];
for (var j = 0; j < coordinates.Length; ++j)
{
await buf.Ensure(SizeOfPoint(type), async);
var position = ReadPosition(buf, type, littleEndian);
boundingBox?.Accumulate(position);
coordinates[j] = position;
}
lines[i] = new LineString(coordinates);
}
geometry = new Polygon(lines);
break;
}
case EwkbGeometryType.MultiPoint:
{
await buf.Ensure(SizeOfLength, async);
var points = new Point[buf.ReadInt32(littleEndian)];
for (var i = 0; i < points.Length; ++i)
{
await buf.Ensure(SizeOfHeader + SizeOfPoint(type), async);
await buf.Skip(SizeOfHeader, async);
var position = ReadPosition(buf, type, littleEndian);
boundingBox?.Accumulate(position);
points[i] = new Point(position);
}
geometry = new MultiPoint(points);
break;
}
case EwkbGeometryType.MultiLineString:
{
await buf.Ensure(SizeOfLength, async);
var lines = new LineString[buf.ReadInt32(littleEndian)];
for (var i = 0; i < lines.Length; ++i)
{
await buf.Ensure(SizeOfHeaderWithLength, async);
await buf.Skip(SizeOfHeader, async);
var coordinates = new Position[buf.ReadInt32(littleEndian)];
for (var j = 0; j < coordinates.Length; ++j)
{
await buf.Ensure(SizeOfPoint(type), async);
var position = ReadPosition(buf, type, littleEndian);
boundingBox?.Accumulate(position);
coordinates[j] = position;
}
lines[i] = new LineString(coordinates);
}
geometry = new MultiLineString(lines);
break;
}
case EwkbGeometryType.MultiPolygon:
{
await buf.Ensure(SizeOfLength, async);
var polygons = new Polygon[buf.ReadInt32(littleEndian)];
for (var i = 0; i < polygons.Length; ++i)
{
await buf.Ensure(SizeOfHeaderWithLength, async);
await buf.Skip(SizeOfHeader, async);
var lines = new LineString[buf.ReadInt32(littleEndian)];
for (var j = 0; j < lines.Length; ++j)
{
var coordinates = new Position[buf.ReadInt32(littleEndian)];
for (var k = 0; k < coordinates.Length; ++k)
{
await buf.Ensure(SizeOfPoint(type), async);
var position = ReadPosition(buf, type, littleEndian);
boundingBox?.Accumulate(position);
coordinates[k] = position;
}
lines[j] = new LineString(coordinates);
}
polygons[i] = new Polygon(lines);
}
geometry = new MultiPolygon(polygons);
break;
}
case EwkbGeometryType.GeometryCollection:
{
await buf.Ensure(SizeOfLength, async);
var elements = new IGeometryObject[buf.ReadInt32(littleEndian)];
for (var i = 0; i < elements.Length; ++i)
{
elements[i] = (IGeometryObject) await ReadGeometryCore(buf, async, boundingBox);
}
geometry = new GeometryCollection(elements);
break;
}
default:
throw UnknownPostGisType();
}
geometry.CRS = crs;
return(geometry);
}
